Develop Reference

Match CalendarView value with Firebase date value then show within Recycler/CardView?

I am attempting to implement my own CardView within a Fragment following previous help from another SO user. I think I have done everything correctly however I am not seeing the expected results and think the fault is elsewhere..
What I have is a CalendarView within a Fragment which displays the selected date inside a TextView using setOnDateChangeListener. I then have a hidden RecyclerView which has a CardView within that, which I am trying to call if the CalendarView date matches the date stored in my Firebase database.. Still with me?
I am creating an event schedule, using a form which has event name, date, time, description, all stored as strings, see below:
I have no idea how to retrieve the push() value when referencing my database so I have just used the event name for ease at the moment..
Here is what I have, it is a bit all over the place as I have been testing here and there but please let me know if you have questions.. I tried separating my database references to use them in different areas but this did not work either.
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_schedule, container, false);
intentEvent = getActivity().getIntent().getStringExtra("name");
// ------------- firebase --------------
firebaseAuth = FirebaseAuth.getInstance();
currentUser = firebaseAuth.getCurrentUser();
uid = currentUser.getUid();
databaseReference = FirebaseDatabase.getInstance().getReference("user").child(uid).child("dogs").child(intentEvent);
eventReference = databaseReference.child("events");
dateRef = eventReference.child("date");
// -------------------------------------
calendarView = view.findViewById(R.id.calendarView);
scheduleTitle = view.findViewById(R.id.scheduleTitle);
noEventPlaceholder = view.findViewById(R.id.noEventPlaceholder);
addNewEvent = view.findViewById(R.id.addNewEvent);
eventRecycler = view.findViewById(R.id.eventRecycler);
eventRecycler.setVisibility(View.GONE);
eventLayoutManager = new LinearLayoutManager(getContext());
eventRecycler.setLayoutManager(eventLayoutManager);
FirebaseRecyclerOptions<Event> options
= new FirebaseRecyclerOptions.Builder<Event>()
.setQuery(databaseReference, Event.class)
.build();
eventAdapter = new EventAdapter(options, new EventAdapter.EventCallback() {
#Override
public void onCardViewClick(Event event) {
// view event in full?
}
});
if (eventReference == null) {
addNewEvent.setVisibility(View.VISIBLE);
noEventPlaceholder.setText("Nothing planned for today.. Let's go walkies!");
} else {
eventRecycler.setVisibility(View.VISIBLE);
}
eventRecycler.setAdapter(eventAdapter);
getEventData();
dog = new Dog();
calendarView
.setOnDateChangeListener(
new CalendarView
.OnDateChangeListener() {
#Override
public void onSelectedDayChange(
#NonNull CalendarView view,
int year,
int month,
int dayOfMonth)
{
String date
= dayOfMonth + "-"
+ (month + 1) + "-" + year;
scheduleTitle.setText(date);
}
});
// this is an example of what i am trying to do..
if (String.valueOf(dateRef).equals(scheduleTitle)) {
eventRecycler.setVisibility(View.VISIBLE);
noEventPlaceholder.setText("Nothing planned for today.. Let's go walkies!");
}
// ---------------------------------------------
addNewEvent.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
databaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String name = dataSnapshot.child("name").getValue(String.class);
Intent intentEventForm = new Intent(getContext(), EventForm.class);
intentEventForm.putExtra("name", name);
startActivity(intentEventForm);
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.w("TAG", "onCancelled", databaseError.toException());
}
});
}
});
return view;
}
public void getEventData() {
eventReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String eventName = dataSnapshot.child("name").getValue(String.class);
String eventDate = dataSnapshot.child("date").getValue(String.class);
String eventTime = dataSnapshot.child("time").getValue(String.class);
String eventDescription = dataSnapshot.child("description").getValue(String.class);
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.w("TAG", "onCancelled", databaseError.toException());
}
});
}

Recyclerview load more lost item click when scrolling

I have a problem with Recyclerview item click. I fetch data to list() method and add via addItem() method in recyclerview custom adapter when scroll down in addOnScrollListener. I get item position with click interface on Fragment. First fetch data work perfectly but when fetch loadmore, can't retrive item positon to new data with onButtonLClick() method.
// in onBindViewHolder;
holder.lnl.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
try {
rcylviewItemNotify.onButtonLClick(position);
}catch (Throwable e){
//interface can be null
}
}
});
// addItem() method in adapter;
public void addItem(List<Image> img) {
for (Image im : img) {
arrayList.add(im);
}
notifyDataSetChanged();
}
// interface code;
public interface RcylviewItemNotify {
void onButtonLClick(int position);
}
// in Fragment code;
public void list() {
GetServices service = RetrofitInstance.getRetrofitInstance().create(GetServices.class);
Call<Images> call = service.getImages();
call.enqueue(new Callback<Images>() {
#Override
public void onResponse(Call<Images> call, Response<Images> response) {
Images body = response.body();
records = body.getImages();
adapter.addItem(records);
}
#Override
public void onFailure(Call<Images> call, Throwable t) {
Toast.makeText(getActivity(), "Network hatası onFailure", Toast.LENGTH_SHORT).show();
reflesh.setRefreshing(false);
}
});
}
#Override
public void onButtonLClick(int position) {
final String clickId = String.valueOf(records.get(position).getID());
Toast.makeText(getActivity(), "ID: " + clickId, Toast.LENGTH_SHORT).show();
}
// recycler settings;
public void loadView() {
layoutManager = new GridLayoutManager(getActivity(), 2);
recyclerView.setLayoutManager(layoutManager);
Collections.reverse(records);
adapter = new RecyclerViewAdapter(this,(ArrayList<Image>) records, getActivity());
recyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
reflesh.setRefreshing(false);
}

I'm not sure if this is your issue but you should be using the ViewHolder to get the position. Inside of your onBindViewHolder:
#Override
public void onClick(View view){
int itemPosition = holder.getAdapterPosition();
// Then do whatever you need to with the position
}

What is a better alternative to valueEventListener for retrieving data from firebase database?

My Firebase database is like that -
users -
first user ID
- name - "abc"
- image - "url"
- one_word - "abc"
following -
first user ID -
second User ID - "0"
Following node shows that First user is following second user.
Here is my code -
#Override
protected void onStart() {
super.onStart();
imageView.setVisibility(View.GONE);
FirebaseRecyclerAdapter<followers_following_class,following_Adapter>firebaseRecyclerAdapter =
new FirebaseRecyclerAdapter<followers_following_class, following_Adapter>
(
followers_following_class.class,
R.layout.find_friend_card,
following_Adapter.class,
databaseReference
) {
#Override
protected void populateViewHolder(final following_Adapter viewHolder, final followers_following_class model, int position) {
final String user_id = getRef(position).getKey();
users.child(user_id).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
final String name = dataSnapshot.child("name").getValue().toString();
final String image = dataSnapshot.child("image").getValue().toString();
final String line = dataSnapshot.child("line").getValue().toString();
final String wins = dataSnapshot.child("one_word").getValue().toString();
viewHolder.setName(name);
viewHolder.setImage(following.this,image);
viewHolder.setLine(line);
viewHolder.setOne_word(wins);
if(getItemCount() == 0){
imageView.setVisibility(View.VISIBLE);
}
viewHolder.vieww.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(!user_id.equals(my_id)){
Intent intent = new Intent(following.this,Friend_profile_view.class);
intent.putExtra("user_id",user_id);
intent.putExtra("image",image);
intent.putExtra("one_word",wins);
intent.putExtra("name",name);
startActivity(intent);
}
}
});
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
};
list.setAdapter(firebaseRecyclerAdapter);
}
public static class following_Adapter extends RecyclerView.ViewHolder {
View vieww;
public following_Adapter(View itemView) {
super(itemView);
this.vieww = itemView;
}
public void setImage( final following following, final String image) {
final CircleImageView circleImageView = (CircleImageView)vieww.findViewById(R.id.find_friend_profile_image_card);
if(!image.equals("default_image")) {
Picasso.with(following).load(image).networkPolicy(NetworkPolicy.OFFLINE).into(circleImageView, new Callback() {
#Override
public void onSuccess() {
}
#Override
public void onError() {
Picasso.with(following).load(image).into(circleImageView);
}
});
}
}
public void setName(String name) {
TextView textView = (TextView)vieww.findViewById(R.id.find_friends_name_card);
textView.setText(name);
}
public void setLine(String line) {
ImageView imageView = (ImageView)vieww.findViewById(R.id.online_or_not);
if(line.equals("offline")){
imageView.setVisibility(View.INVISIBLE);
}
}
public void setOne_word(String wins) {
TextView textView = (TextView)vieww.findViewById(R.id.user_level);
textView.setText(wins);
}
}
Is there any way where i can apply firebase recycler adapter for one node but retrieve data form another node with same key without using addValueEventListener ?
And also most of my app uses firebase recyclerview in all activities so when i observed my android profiler , my RAM usage is increasing while switching between activities i have also used finish(); ended the addValuelistener in onDistroy method but it is still not working.

There are 3 eventListeners that you can use according to your needs, namely valueEventListener, childEventListener and singleValueEventListener.
This will be a good read for this, Firebase Docs.
When working with lists, your application should listen for child events rather than the value events used for single objects.
Child events are triggered in response to specific operations that happen to the children of a node from an operation such as a new child added through the push() method or a child being updated through the updateChildren() method. Each of these together can be useful for listening to changes to a specific node in a database.
In code, childEventListener looks like this:
ChildEventListener childEventListener = new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String previousChildName) {
Log.d(TAG, "onChildAdded:" + dataSnapshot.getKey());
// A new comment has been added, add it to the displayed list
Comment comment = dataSnapshot.getValue(Comment.class);
// ...
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String previousChildName) {
Log.d(TAG, "onChildChanged:" + dataSnapshot.getKey());
// A comment has changed, use the key to determine if we are displaying this
// comment and if so displayed the changed comment.
Comment newComment = dataSnapshot.getValue(Comment.class);
String commentKey = dataSnapshot.getKey();
// ...
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
Log.d(TAG, "onChildRemoved:" + dataSnapshot.getKey());
// A comment has changed, use the key to determine if we are displaying this
// comment and if so remove it.
String commentKey = dataSnapshot.getKey();
// ...
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String previousChildName) {
Log.d(TAG, "onChildMoved:" + dataSnapshot.getKey());
// A comment has changed position, use the key to determine if we are
// displaying this comment and if so move it.
Comment movedComment = dataSnapshot.getValue(Comment.class);
String commentKey = dataSnapshot.getKey();
// ...
}
#Override
public void onCancelled(DatabaseError databaseError) {
Log.w(TAG, "postComments:onCancelled", databaseError.toException());
Toast.makeText(mContext, "Failed to load comments.",
Toast.LENGTH_SHORT).show();
}
};
ref.addChildEventListener(childEventListener);
Also, retrieving data without the use of eventListeners is not possible. And if you want to listen to children of your one node, simultaneously, then childEventListener will be a great tool.

How to retrieve data from firebase using MVC pattern in Android? [duplicate]

This question already has answers here:
How to return DataSnapshot value as a result of a method?
(6 answers)
Closed 4 years ago.
I'm working on a simple Android project which can insert and retrieve data from Firebase. The inserting function works well, which means the project has successfully connected to the Firebase database. However, the retrieving part doesn't work. I did many tests and think the problem is in the FirebaseHelper because when I tried to print the result of "firebasehelper.retrieveMajor()" in the Activity, it shows nothing. But it did show the data when printing data in FirebaseHelper. You can see the codes as followings.
Model:
#IgnoreExtraProperties
public class Major {
public String major_id;
public String major_name;
public Major() {
}
public Major(String major_id, String major_name) {
this.major_id = major_id;
this.major_name = major_name;
}
public String getMajor_id() {
return major_id;
}
public String getMajor_name() {
return major_name;
}
}
Adapter:
public class MajorListAdapter extends BaseAdapter {
Context context;
ArrayList<Major> majors;
public MajorListAdapter(Context context, ArrayList<Major> majors) {
this.context = context;
this.majors = majors;
}
#Override
public int getCount() {
return majors.size();
}
#Override
public Object getItem(int pos) {
return majors.get(pos);
}
#Override
public long getItemId(int pos) {
return pos;
}
#Override
public View getView(int position, View convertView, ViewGroup viewGroup) {
if(convertView==null)
{
convertView= LayoutInflater.from(context).inflate(R.layout.model,viewGroup,false);
}
TextView tv_majorid= (TextView) convertView.findViewById(R.id.tx_majorid);
TextView tv_majorname= (TextView) convertView.findViewById(R.id.tx_majorname);
final Major major= (Major) this.getItem(position);
tv_majorid.setText(major.getMajor_id());
tv_majorname.setText(major.getMajor_name());
return convertView;
}
}
FirebaseHelper:
public class FirebaseHelper {
DatabaseReference db;
Boolean saved=null;
ArrayList<Major> majors = new ArrayList<>();
public FirebaseHelper(DatabaseReference db) {
this.db = db;
}
//Save the Major info. into db
public Boolean saveMajor(Major major)
{
if(major==null)
{
saved=false;
}else
{
try
{
db.child("Major").push().setValue(major);
saved=true;
}catch (DatabaseException e)
{
e.printStackTrace();
saved=false;
}
}
return saved;
}
private void fetchDataFromMajor(DataSnapshot dataSnapshot) {
majors.clear();
for (DataSnapshot ds : dataSnapshot.getChildren()) {
Major major = ds.getValue(Major.class);
majors.add(major);
}
}
public ArrayList<Major> retrieveMajor() {
db.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(DataSnapshot dataSnapshot, String s) {
fetchDataFromMajor(dataSnapshot);
}
#Override
public void onChildChanged(DataSnapshot dataSnapshot, String s) {
fetchDataFromMajor(dataSnapshot);
}
#Override
public void onChildRemoved(DataSnapshot dataSnapshot) {
}
#Override
public void onChildMoved(DataSnapshot dataSnapshot, String s) {
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
return majors;
}
}
The Activity that retrieves data and binds the data with the ListView:
public class MajorListActivity extends AppCompatActivity {
DatabaseReference db;
FirebaseHelper firebasehelper;
MajorListAdapter adapter;
ListView lv_MajorList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_major_list);
lv_MajorList = (ListView) findViewById(R.id.lv_MajorList);
db= FirebaseDatabase.getInstance().getReference();
firebasehelper=new FirebaseHelper(db);
//ADAPTER
adapter = new MajorListAdapter(getApplicationContext(),firebasehelper.retrieveMajor());
lv_MajorList.setAdapter(adapter);
}
}

Firebase APIs are asynchronous, meaning that they return immediately, before the results of your query are complete. Some time later, your callback will be invoked with the results. This means that your retrieveMajor function is returning whatever is in the array majors, before the query finishes.
You'll need to correctly handle the asynchronous nature of Firebase APIs, which means that you can't write methods that directly return data that you fetch from the database. You'll have to use the callbacks to wait for results, then update your UI as needed.
To learn more about why Firebase APIs are asynchronous and what to expect from them, read this article.

It prints the data because your ArrayList is being populated, but asynchronously, after you pass it to your Adapter.
The adapter holds a reference to the same ArrayList that is later getting populated via your Firebase callbacks, but the adapter itself needs to be notified using notifyDataSetChanged() when there is new data in the array, otherwise it won't check for it.
Basically, you need to find a way to notify your adapter of the dataset changing every time you get new data from Firebase. A simple mechanism to use would be a callback.

CheckBox state inside RecyclerView

I created a Checkbox, however, whenever I click a few Items random checkboxes become clicked. I have a recycler view, and I have an adapter class as well. Here is my CheckBox method can anyone tell me the problem?
public void CheckBox(View view) {
final CheckBox checkBox = (CheckBox)view;
if (checkBox.isChecked()) {
System.out.println("SET TO CHECKED");
//Input instance of selected course(CHECKED)
// TODO: 2/5/16 Need to pass in Persisted ID
mVolleySingleton = VolleySingleton.getInstance();
mRequestQueue = mVolleySingleton.getRequestQueue();
CharSequence ID_PUT_COURSES = ((TextView) ((RelativeLayout) view.getParent()).getChildAt(1)).getText();
System.out.println(PUT);
String URL_PUT_COURSES = "URL"+ID_PUT+"\n";
System.out.print(PUT);
StringRequest UrlPut = new StringRequest(Request.Method.PUT, URL_PUT, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
System.out.println(response + "reponse");
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
System.out.println("************Answer" + error + "error");
}
});
mRequestQueue.add(UrlPutCourses);
System.out.println("Added");
}
else{
System.out.println("SET TO UNCHECKED");
//delete instance of selected course(UNCHECKED)
mVolleySingleton = VolleySingleton.getInstance();
mRequestQueue = mVolleySingleton.getRequestQueue();
// TODO: 2/5/16 Need to pass in Persisted ID
CharSequence DELETE = ((TextView) ((RelativeLayout) view.getParent()).getChildAt(1)).getText();
System.out.print(ID_PUT_COURSES);
String UR_DELETE = "URL"+ DELETE;
StringRequest UrlDeleteCourses = new StringRequest(Request.Method.DELETE, UR_DELETE, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
System.out.println(response + "reponse");
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
error.printStackTrace();
System.out.println("************Answer" + error + "error");
}
});
mRequestQueue.add(UR_DELETE);
System.out.println("Deleted");
}
}
ublic class AdapterSearch extends RecyclerView.Adapter<AdapterSearch.ViewSearch>{
private LayoutInflater mLayoutInflater;
private ArrayList<Search> ListSearch=new ArrayList<>();
public AdapterSearch(Context context){
mLayoutInflater=LayoutInflater.from(context);
}
public void setListSearch(ArrayList<Search> ListSearch){
this.ListSearch=ListSearch;
notifyItemRangeChanged(0,ListSearch.size());
}
#Override
public ViewSearch onCreateViewHolder(ViewGroup parent, int viewType) {
View view= mLayoutInflater.inflate(R.layout.custom_search,(ViewGroup)null);
ViewSearch holder=new ViewSearch(view);
return holder;
}
#Override
public void onBindViewHolder(ViewSearch holder, int position) {
Search currentSearch=ListSearch.get(position);
holder.mSearchText.setText(currentSearch.getMtitle());
holder.mAnswerPointsSearch.setText(currentSearch.getMkey());
holder.mSearchId.setText(currentSearch.getMid());
holder.mCourseId.setText(currentSearch.getCourseId());
}
#Override
public int getItemCount() {
return ListSearch.size();
}
public void setFilter(ArrayList<Search> Search) {
ListSearch = new ArrayList<>();
ListSearch.addAll(Search);
notifyDataSetChanged();
}
static class ViewSearch extends RecyclerView.ViewHolder{
private TextView mSearchText;
private TextView mAnswerPointsSearch;
private TextView mSearchId;
private TextView mCourseId;
public ViewSearch (View view){
super(view);
mSearchText=(TextView)itemView.findViewById(R.id.SearchText);
mAnswerPointsSearch=(TextView)itemView.findViewById(R.id.AnswerPointsSearch);
mSearchId=(TextView)itemView.findViewById(R.id.SearchId);
mCourseId=(TextView)itemView.findViewById(R.id.CourseTextView);
}
}
}

Better late then never I'd say, it might help other people stumbling upon this issue later, so here goes.
This might not be the best solution ever, but it should work.
In your Search class, you have some variables like title and key. Add the boolean isChecked to it, and make it false by default. Also create the matching getter and setter. (I'm using isChecked() & setChecked() in this example)
In your onBindViewHolder() method, add the following lines:
CheckBox checkBox = (CheckBox) itemView.findViewById(R.id.CheckBoxID);
// Instantiating the checkbox
holder.checkBox.setChecked(currentSearch.isChecked());
// Every time the holder (one list item) is shown, this gets called.
// It sets the checked state based on what's stored in currentSearch.
checkBox.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (checkBox.isChecked()) {
currentSearch.setChecked(true)
} else {
currentSearch.setChecked(false);
}
});
}
// This listens for clicks on the checkbox, and changes the checked state of
// the boolean in currentSearch to the correct state based on
// what it already was on.
Please be aware that I haven't worked with checkboxes before, so some things (like setting the checked state) might be done slightly differently from what I've described above, but this should be a working base.
You also probably want the checkboxes to only persevere until you click a button or something like that, and then have them reset. You might want to add a simple for loop for that, something like:
public void resetAllCheckBoxes() {
for (Search s : ListSearch) {
s.setChecked(false);
}
}